1. Field
Apparatuses and methods consistent with exemplary embodiments relate to photographing an image with light leakage correction, and more particularly to photographing an image by correcting light leakage occurring in a global shutter.
2. Description of the Related Art
There are generally two types of image sensors that electrically convert light received into a lens of a photographing apparatus: a charge-coupled device (CCD) sensor and a complementary metal oxide semiconductor (CMOS) sensor.
Both types of sensors retain adequate light leakage by operation of a shutter that adjusts amounts of light by initiating and/or ending light exposure. The shutter may be operated under various electronic shutter mechanisms such as, for example, rolling shutter and global shutter.
In the rolling shutter method, an image sensor does not have a storage that stores charges accumulated in a photo diode at each pixel, and thus light exposure is initiated and ended consecutively for each pixel. In other words, the photodiodes at each pixel do not collect light at the same time. All the pixels in one row of the image sensor collect light during the same period of time, but the time that light collection starts and ends is slightly different for each row.
In the global shutter method, light exposure is initiated in all the pixels of an image sensor simultaneously, and after an adequate light exposure time, using a storage provided per pixel, light exposure ends in all the pixels simultaneously.
However, in a CMOS type global shutter, when a global shutter operates, after photo-generated charges are stored in pixel-level storages until the charges are read out, a light leakage phenomenon may occur and therefore the photo-generated charges in the pixel-level storages may leak into surrounding pixels related to a high luminance subject. For example, in the case of a pixel that is read out the latest, the light leakage phenomenon becomes more severe in proportion to the period of time the readout is performed.